Juraj Gašper

Various genetic and environmental factors influence the composition of milk. For the cheese manufacturing industry, one of the most important genes is the CSN1S1 gene, which influences the composition of several milk components as well as technological properties. Much attention has been paid to the F allele, which has been identified as undesirable for the manufacturing cheese. The aim of this study was to determine the genotypic structure of the Slovak population of the Slovak White Shorthaired goat (Capra hircus) for the CSN1S1 gene and to evaluate the influence of the CSN1S1 F allele on milk composition characteristics. Hair roots of 86 goats were collected and used as genetic material. Genotyping was performed using PCR and PIRA PCR. Phenotypic data from 101 lactations (first and/or second lactation only) with performance control were used for association studies. The occurrence of the F allele was 0.291. An association study was performed between genotypes consisting of F and non-F alleles. Significantly higher (p >.05) milk, protein, lactose and dry matter production was observed in non-F/non-F individuals than in F/non-F individuals. Genotyping of the CSN1S1 gene could be the basis for the use of marker-assisted selection in a breeding programme for the Slovak White Shorthorn goat. Further analyses involving the effect of the CSN1S1 genotype on cheese production could be performed to quantify the impact of composition on farm economics.

Infant formula is the main source of nutrition for babies who cannot be fed human milk, which is the best source of feed for them. Modern trends spreading through social media are questioning the suitability of commercial infant formula for children. The growth in cow's milk protein allergies among the population and the increase in the percentage of premature infants with low birth weight are focusing attention on cow's milk-based infant formula substitutes. Recently, goat's milk-based infant formulas have become available. A comparison of the composition requirements of infant formula and premature infant formula shows the need to modify both milks for use in infant formula. Differences in milk composition and functional properties can compensate for technological and nutritional differences. The lower allergenicity of goat milk, smaller fat globules and softer curd can cause a different body reaction in goat's milk based infant formula than cow's milk based infant formula. The choice of commercial infant formula should not be made based on the reactions of other children but should be selected taking into account the individual's ability to grow and develop appropriately during the use of particular infant formula.

Milk is an important component of human nutrition, and its composition and milk yield fundamentally affect the economy of dairy farms. Genetic variability is a fundamental premise for livestock breeding and is commonly used in the identification of individual animals and in selection to improve performance. The aims of this study were to propose a rapid detection method for genes affecting the nutritional value and technological properties of bovine milk (FADS1, FADS2, FASN, SCD, DGAT1, CSN2 and CSN3) and to analyze Slovak Holstein cattle to widen knowledge on their genetic structure for these candidate genes. Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and artificially created restriction site-polymerase chain reaction (ACRS-PCR) methods. Heterozygosity is an important factor for estimating genetic variation in domestic animals and represents the genetic potential and ability to adapt to the natural environment. In this study, Holstein cattle showed high heterozygosity values for markers FADS1-07 and CSN2-H67P. In contrast, they showed high homozygosity values for markers FADS1-01, FADS2-23, FASN-16024, SCD-T878C, DGAT1-K232A and CSN3-D148A. These results suggest that genetic diversity has been reduced, which may be due to breeding effects.